It is planned to perform an in depth analysis of IL-2 pathophysiology in human immunodeficiency syndromes (IDS). These studies will focus on the following diagnostic categories as well as on appropriate controls: (1)\congenital IDS; (2)\IDS of unknown etiology: (a)\CVI, (b)\AIDS with and without Kaposi's sarcoma; (3)\Therapy/Cancer associated IDS: (a)\Hodgkin's disease prior to and after therapy, (b)\ovarian carcinoma prior to and after high dose chemotherapy, (c)\breast cancer prior to and on adjuvant chemotherapy, (d)\patients prior to and after allogeneic and autologous bone marrow transplantation. The in vitro studies planned will evaluate IL-2 production and response (IL-2 P/R) of total mononuclear cell fractions (PBL) as well as of isolated PBL subsets. We will investigate: (1)\the biochemical (different molecular species), biological (different targets) and immunological properties of IL-2 produced by PBL and PBL subsets through further purification of IL-2 subspecies and generation of IL-2 subtype specific monoclonals; (2)\the effect of other cell types on IL-2 P/R, e.g., monocytes, NK cells, suppressor and helper T cells through mixing experiments of PBL subsets; (3)\the role of other lymphokines (e.g., Interferon alpha, gamma, Interleukin 1) and pharmacological agents (e.g., cimetidine, indocine, cyclosporin A) on IL-2 P/R of PBL and PBL subsets; (4)\the biological effect of monoclonal reagents recognizing antigens of regulatory significance in IL-2 physiology (e.g., anti IL-2, anti IL-2 receptor, OKT3, Pan T2, anti Ia, anti HLA) on IL-2 P/R of PBL and PBL subsets. In addition to routine immunological phenotyping, we will attempt to characterize IL-2 producer and responder cells through the use of anti-IL-2 and anti-IL-2 receptor antibodies by immunofluorescence and PAP techniques.